I was instructed to do this regularly with my son by his Pediatrician. The Doctor seemed concerned when it would not retract at one point (he made sure he got it where it would by using some gel in his office.) I would ask your Doc about it instead of letting it go.
South, why would they say not to retract it during childhood as it does need to be kept clean under the folds...especially when they are wearing diapers?
Seriously - all my info comes from uncut Europeans and their docs and they all say - leave it be - there is no need to pull the foreskin of a young child back to clean it (though many American doctors give this advice because they don't have as much experince with uncut penises and because we think we need to clean the heck out of everything over here). If you retract it before it is ready - it will tear - and that's where problems and infections start.
The skin will start to retract naturally as the child matures. We've never touched our sons's foreskins - I do tell them to soap up in the shower, but no more than a cut male would do - and there's no odor, dirt, weirdness, problems. It's just a piece of skin. Again - most men on the planet are uncut and don't do anything special to it as kids and everything turns out fine.
ETA - My American doc actually told us to pull the foreskin back of our tiny sons and clean it, and my husband and his Dad (a doctor) said "Rubbish!" I decided to listen to the men who've been dealing with uncut penises for generations.